1. Field of the Invention
The present invention has to do with a process for manufacturing mechanically embossed synthetic surface coverings and the products obtained thereby. More particularly, the invention relates to floor coverings which are mechanically embossed and processed to create selectively embossed surface areas, thereby creating products having a more realistic appearance. These appearances include, for example, ceramic tile, stone, brick, sandstone, cork, wood, and in some embodiments textured lines or grout lines there between, as well as combinations thereof such as sandstone and ceramic tile, textured wood and smooth ceramic, cork and wood, and stone or slate in combination with ceramic tile.
2. Description of the Related Art
Synthetic surface coverings including sheet flooring, wall coverings and tile are employed in residential, commercial and institutional applications where decorative effects, durability and ease of installation and maintenance are important considerations. These surface coverings can be designed to imitate a variety of masonry materials such as ceramic tile, stone and brick or they can be designed with unique combinations of color, particles and other decorative features that are not available in other types of surface coverings. In the current marketplace, consumers are increasingly demanding synthetic surface coverings with improved textural features such as features which realistically imitate not only the textures of materials such as ceramic tile, stone, brick, sandstone, cork, wood and combinations thereof, but also the texture of the grout or mortar which typically is used by a mason or other craftsman to fill the joints between such materials to secure them in their desired position relative to one another.
The surface covering industry has employed mechanical embossing, chemical embossing, combinations of mechanical and chemical embossing, screen printing and other techniques for years in order to obtain design effects and textures which meet consumer demands. In U.S. Pat. No. RE. 33,599 a process is described for obtaining selective matting on synthetic coverings by depositing on an expandable or nonexpandable support substrate (1) a polymer coating which contains at least one first polymerization initiator onto at least a first selected zone and (2) at least one second coating comprised of a crosslinkable monomer which contains at least one second polymerization initiator onto at least a second selected zone. The second zone may encompass at least a portion of the first zone. The first and second initiators are triggered by distinct “spectral zones”. Following pre-gelling, an overall graining operation is carried out over at least a portion of the surface followed by curing the first selected zone and thereby fixing the graining thereon. Then gelling is carried out to cause the graining in the second zone to smooth out. The product has a selectively matted appearance. Another method of making differential gloss products is described in U.S. Pat. No. 4,298,646.
The surface texture effects of the present invention are obtained by creating relatively deep emboss depths as compared with the shallow graining or dusting techniques employed to obtain the matted or differential gloss effects of the patents noted above. More specifically, the present invention is directed to the realistic imitation in surface coverings not only of the surface texture of a variety of masonry materials such as ceramic tile, stone, brick, sandstone, cork, wood and combinations thereof, but also in some embodiments to the realistic imitation of the surface texture of the grout or mortar in the joints between such materials.